TWI760870B - Soldering process monitoring system and method - Google Patents

Abstract

The present disclosure provides a soldering process monitoring system and method. The soldering process monitoring system includes a tin supply unit, a soldering iron, a temperature sensing unit and a processing unit. The tin supply unit is configured to supply the tin. The soldering iron has an end part, which is heated for melting the tin while being contacted with the tin. During a first period after the end part being contacted with the tin, the temperature of the end part is decreased by a first variation amount in total. During the end part being contacted with the tin, the temperature of the end part is decreased by a second variation amount in total. The processing unit acquires the first and second variation amounts through the temperature sensing unit, and calculates a temperature decreasing speed of the temperature of the end part during the first period. The processing unit compares the temperature decreasing speed and the second variation amount with a first reference value and a second reference value respectively. According to the comparing result, the processing unit outputs a monitoring signal.

Description

Soldering process monitoring system and method

This case is about a soldering process monitoring system and method, especially a soldering process monitoring system and method that can instantly understand the soldering quality.

The soldering process uses a soldering iron tip heated at a high temperature to melt solder metal with a lower melting point, thereby connecting metal workpieces. The quality of the solder is closely related to the details in the process, including whether the soldering iron actually melts the tin and whether the amount of molten tin and residual tin of the soldering iron is as expected.

In the prior art, after the soldering process is completed, inspection can be performed by visual equipment such as automatic optical inspection (AOI) to confirm the soldering quality. However, the existing technology cannot monitor and adjust the quality of the soldering process in real time, which will affect the operation efficiency of the soldering process. In addition, the high cost of vision equipment for quality inspection results in increased costs.

Therefore, how to develop a soldering process monitoring system and method that can improve the above-mentioned conventional technology is an urgent need.

The purpose of this case is to provide a soldering process monitoring system and method, which monitors the soldering quality through the temperature change of the end of the soldering iron during the soldering process, so that when the soldering quality is not good, it can be immediately known and adjusted, and the soldering can be effectively improved. Process quality stability and operating efficiency. In addition, in this case, there is no need to use additional visual equipment for quality inspection, which can save costs.

In order to achieve the above purpose, the present application provides a soldering process monitoring system, which includes a tin feeding unit, a soldering iron, a temperature sensing unit and a processing unit. The tin feeding unit is structured to provide tin material. Soldering irons have tips where the tips are heated to melt the tin material when it contacts it. During the first time period after the end portion contacts the tin material, the temperature of the end portion decreases by the first change amount, and during the process of the end portion being in contact with the tin material, the temperature of the end portion decreases by the second change amount. The temperature sensing unit is constructed to sense the temperature of the end of the soldering iron to obtain multiple pieces of temperature information. The processing unit is connected to the temperature sensing unit to receive the temperature information, and calculate and obtain the first change amount and the second change amount according to the temperature information. The processing unit calculates and obtains the temperature drop rate of the temperature of the end portion in the first time period, and compares the temperature drop rate and the second variation with the first reference value and the second reference value respectively, and outputs a monitoring signal according to the comparison result. .

In order to achieve the above purpose, the present application further provides a method for monitoring a soldering process, comprising the steps of: (a) continuously sensing the temperature of the tip of the soldering iron; (b) heating the tip and contacting the tip with a tin material, wherein at the tip In the first time period after the part contacts the tin material, the temperature of the end part is sensed to obtain a plurality of pieces of temperature information; (c) according to the temperature information, the first change of the temperature drop in the first time period is calculated and obtained, and the calculation Obtain the temperature drop rate in the first time period; (d) compare the temperature drop rate with the first reference value, and output the first monitoring signal according to the comparison result; (e) separate the tin material from the end, wherein the end In the process of contacting with the tin material, the temperature of the end is sensed and a plurality of pieces of temperature information are obtained; and (f) according to the temperature information, a second variation of the temperature drop of the end is obtained by calculating and comparing the second variation and The second reference value is outputted according to the comparison result.

Some typical embodiments embodying the features and advantages of the present case will be described in detail in the description of the latter paragraph. It should be understood that this case can have various changes in different aspects, all of which do not depart from the scope of this case, and the descriptions and diagrams therein are essentially for illustration purposes rather than limiting the present case.

FIG. 1 is a schematic structural diagram of a soldering process monitoring system according to a preferred embodiment of the present invention. As shown in FIG. 1 , the soldering process monitoring system includes a tin feeding unit 1 , a soldering iron 2 , a temperature sensing unit 3 and a processing unit 7 . The tin feeding unit 1 is structured to provide tin material 11 . The soldering iron 2 has an end portion 21 , wherein the end portion 21 is heated to melt the tin material 11 upon contact with the tin material 11 . The temperature sensing unit 3 senses the temperature of the end 21 of the soldering iron 2 in a contact or non-contact manner; the temperature sensing unit 3 is connected to the processing unit 7 , and the temperature sensing unit 3 will sense the acquired temperature information of the end 21 of the soldering iron 2 It is sent to the processing unit 7 for processing. In some embodiments, the solder process monitoring system further includes a temperature controller 4 . The temperature controller 4 is connected to the soldering iron 2 and configured to control the temperature of the end 21 of the soldering iron 2 .

Taking the soldering process applied to the printed circuit board as an example, the specific monitoring method of the soldering process monitoring system in this case is explained as follows.

In the soldering process, the pins 5 of the electronic components pass through the solder joints 6 of the printed circuit board, and the pins 5 and the solder joints 6 are fused by soldering. Please refer to Figure 2 for the action breakdown of the soldering process, which illustrates the action states at different time points during the soldering process, which are action states (a), (b), (c), (d) and (e) in sequence. During the soldering process, the temperature change of the end portion 21 of the soldering iron 2 is shown in FIG. 3 , and the time points or time periods corresponding to each action state are also marked in FIG. 3 .

First, during the preparatory action, neither the end part 21 of the soldering iron 2 nor the tin material 11 provided by the tin feeding unit 1 is in contact with the solder joint 6 (as shown in FIG. 1 ). At this time, the end part 21 can be heated in advance.

Then, as shown in the operating state (a), the end 21 of the soldering iron 2 touches the solder joint 6, and the temperature of the end 21 is maintained at a high temperature, and the temperature of the solder joint 6 also increases accordingly. At this time, the tin material 11 provided by the tin feeding unit 1 still maintains a certain distance from the end portion 21 and the solder joint 6 .

Next, as shown in the action state (b), the tin feeding unit 1 supplies the tin material 11, so that the tin material 11 contacts the end portion 21 or the solder joint 6, and contacts the end portion 21 after the time point corresponding to the action state (b). Or the tin material 11 of the solder joint 6 is melted by high temperature, and the temperature of the end portion 21 is lowered due to the melting of the tin material 11 . Wherein, in the first time period Δt1 after the tin material 11 contacts the end portion 21 or the solder joint 6 , the temperature of the end portion 21 decreases by a first change amount T1 , and this first change amount T1 can be sensed by the temperature sensing unit 3 . The temperature of the end portion 21 is measured and then sent to the processing unit 7 for a plurality of temperature information measured at different times, and the processing unit 7 calculates and obtains, and the processing unit 7 can further calculate and obtain the temperature of the end portion 21 within the first time period Δt1 The rate of decrease, wherein the rate of temperature decrease is equal to the first change amount T1 divided by the first time period Δt1. The first time period Δt1 may be, for example, but not limited to, equal to one unit of time. Since the end portion 21 may be normally melted tin, unmelted or cold welded, and the corresponding temperature drop speeds are different from each other, the processing unit 7 can compare the temperature drop speed with the first reference value, and determine according to the temperature drop speed. The comparison result outputs a first monitoring signal, wherein the first monitoring signal reflects whether the end portion 21 actually melts the tin material.

Next, as shown in the operating state (c), the tin supply unit 1 continues to supply the tin material 11, and the temperature of the end portion 21 continues to drop.

Then, as shown in the action state (d), the tin output from the tin feeding unit 1 has reached the preset tin quantity, and the tin feeding unit 1 stops supplying the tin material 11, so that the tin material 11 is separated from the end portion 21 and the solder joint 6 . During the process that the tin material 11 is in contact with the end portion 21 or the solder joint 6 , the temperature of the end portion 21 decreases by a second amount of change T2 , which can be obtained by the temperature sensing unit 3 by sensing the temperature of the end portion 21 The temperature is then sent to the processing unit 7 for a plurality of temperature information measured at different times, and the processing unit 7 calculates and obtains it. Since the second variation T2 is related to the total amount of the tin material 11 melted by the end portion 21 , the processing unit 7 can compare the second variation T2 with the second reference value, and output the second monitoring signal according to the comparison result, wherein The second monitoring signal reflects whether the total amount of the tin material 11 melted by the end portion 21 is consistent with the preset amount of tin melting.

Finally, as shown in the action state (e), when the end portion 21 is separated from the solder joint 6, the temperature of the end portion 21 will start to rise, and a portion of the previously melted tin material 11 may remain on the end portion 21.

In this way, in the soldering process, the temperature change of the end portion 21 can be used to determine whether there is a problem such as lack of tin or solder leakage in real time, so as to monitor the quality of the solder, and when the quality of the solder is not good, the monitoring signal can be used. Adjustment to effectively improve the quality stability and operation efficiency of the soldering process. In addition, in this case, there is no need to use additional visual equipment for quality inspection, which can save costs.

In addition, within the second time period Δt2 after the time point corresponding to the action state (d), that is, within the second time period Δt2 after the tin material 11 is separated from the end portion 21 or the solder joint 6, the temperature of the end portion 21 The third change amount T3 is increased in total. The third change amount T3 can be sent to the processing unit 7 by the temperature sensing unit 3 by sensing the temperature of the end portion 21 and then sent to the processing unit 7 to measure the temperature information at different times, and calculated by the processing unit 7 After obtaining, the temperature sensing unit 3 transmits the above-mentioned temperature information to the processing unit 7, and the processing unit 7 can further calculate and obtain the temperature recovery speed of the end portion 21 in the second time period Δt2, wherein the temperature recovery speed is equal to the third change amount T3 is divided by the second time period Δt2. The second time period Δt2 may be, for example, but not limited to, equal to one unit of time. The temperature recovery speed is related to the total amount of tin material 11 remaining on the end portion 21 , and the total amount of the tin material 11 remaining on the end portion 21 will affect the effective tin amount on the solder joint 6 . Therefore, the processing unit 7 can compare the temperature recovery speed with the third reference value, and output a third monitoring signal according to the comparison result, wherein the third monitoring signal reflects whether the total amount of tin material remaining on the end portion 21 is the same as the preset value. The amount of residual tin is consistent, so that the effective amount of tin deposited on the solder joint 6 can be estimated, and then it can be judged whether there are problems such as lack of soldering or missing soldering.

The aforementioned first reference value, second reference value and third reference value can be obtained by counting the temperature drop rate, the second change amount and the temperature recovery rate under the ideal solder process state, and the reference value and its corresponding temperature change rate or The comparison method between the changes can also be determined according to the actual needs. A specific example is described below.

Under the conditions of the same pins and solder joints, the soldering process is carried out more than 30 times. During each soldering process, the end 21 of the soldering iron 2 is normally melted, and the total amount of molten tin is 5mm. There is no residual tin material. Record the temperature drop speed V1, the second variation T2 and the temperature recovery speed V2 in Table 1 in all soldering processes.

Table I order V1 (degC/sec) T2 (degC) V2 (degC/sec) 1 0.0434 6.9 0.01620 2 0.0514 6.7 0.01277 3 0.0427 7.0 0.01528 4 0.0410 6.5 0.01517 5 0.0441 5.5 0.01538 … … … … 30 0.0364 6.3 0.01310

(1)

(2) 其中， x為目標數值 (即為溫度下降速度V1、第二變化量T2或溫度回升速度V2)，

為目標數值之平均值， n為實驗總次數， i代表次序， x _i 為相應次序時的目標數值，σ為目標數值的標準差。通過計算獲得的溫度下降速度V1、第二變化量T2及溫度回升速度V2的平均值及標準差係列出於表二。 According to Table 1, the average value and standard deviation of the temperature drop speed V1, the second variation T2 and the temperature recovery speed V2 can be obtained through equations (1) and (2), as shown in Table 2.

(1)

(2) Among them, x is the target value (that is, the temperature drop speed V1, the second change amount T2 or the temperature recovery speed V2),

is the average value of the target value, n is the total number of experiments, i represents the order, x _i is the target value in the corresponding order, and σ is the standard deviation of the target value. The average and standard deviation series of the temperature drop speed V1, the second change amount T2 and the temperature recovery speed V2 obtained through calculation are shown in Table 2.

Table II / V1 T2 V2 average value 0.0408 6.3368 0.0137 standard deviation 0.0033 0.4132 0.0015

According to Table 2, the first reference value, the second reference value and the third reference value can be set as the average value of the temperature drop speed V1, the second change amount T2 and the temperature recovery speed V2, respectively, and the corresponding standard deviations are σ _V1 , σ _T2 and σ _V2 . In the future, when monitoring the soldering process, the reference value can be compared as a benchmark, and the allowable error range can be set according to the corresponding standard deviation. For example, during the soldering process, if V1 ≦+ 3σ _V1 , it means that the end 21 of the soldering iron 2 is normally melted; in the case where the preset amount of solder is 5mm, if + 3σ _T2 ≧ T2 ≧- 3σ _T2 , it means that the amount of molten tin on the end portion 21 is normal; if V2≧- 3σ _V2 , it means that there is no residual tin material on the end portion 21 . Of course, the actual comparison method is not limited to this, and can be adjusted according to actual needs.

FIG. 4 is a schematic flowchart of a solder process monitoring method according to a preferred embodiment of the present invention, wherein the solder process monitoring method can be applied to the solder process monitoring system shown in FIG. 1 . As shown in Figure 4, the solder process monitoring method includes the following steps.

First, in step S1, the temperature of the end portion 21 of the soldering iron 2 is continuously sensed.

Next, in step S2 , the end portion 21 is heated, and the tin material 11 is brought into contact with the end portion 21 , wherein the temperature sensing unit 3 senses the end portion 21 within the first time period Δt1 after the end portion 21 contacts the tin material 11 . The temperature of the part 21 is sent to the processing unit 7 .

In step S3, the processing unit 7 calculates and obtains the first variation T1 of the temperature drop of the end portion 21 according to the multiple pieces of temperature information, and calculates and obtains the temperature drop speed of the end portion 21 temperature within the first time period Δt1.

Next, in step S4 , the processing unit 7 compares the temperature drop rate with the first reference value, and outputs a first monitoring signal according to the comparison result, wherein the first monitoring signal reflects whether the end portion 21 has indeed melted the tin material 11 .

Then, in step S5, the tin material 11 is separated from the end portion 21, wherein during the process of the end portion 21 being in contact with the tin material 11, the temperature sensing unit 3 continuously senses the temperature of the end portion 21, and senses the temperature of the end portion 21. The measured temperature information is sent to the processing unit 7 .

Finally, in step S6, the processing unit 7 calculates and obtains the second change amount T2 of the temperature drop of the end portion 21 according to the multiple pieces of temperature information, compares the second change amount T2 with the second reference value, and outputs the second monitor according to the comparison result. signal, wherein the second monitoring signal reflects whether the total amount of the tin material 11 melted by the end portion 21 is consistent with the preset amount of tin melting.

In addition, in the second time period Δt2 after the end portion 21 is separated from the tin material 11 in step S5, the temperature of the end portion 21 increases. In some embodiments, the solder process monitoring method further includes step S7 : in the second time period Δt2 after the end portion 21 and the tin material 11 are separated, the temperature sensing unit 3 senses the temperature of the end portion 21 , and senses the temperature of the end portion 21 . Sending the measured pieces of temperature information to the processing unit 7; and step S8: the processing unit 7 calculates and obtains the third change amount T3 of the temperature rise of the end portion 21 according to the plurality of pieces of temperature information, and calculates and obtains the end portion 21 in the second time period Δt2 and comparing the temperature rising speed with the third reference value, so as to output the third monitoring signal according to the comparison result. After the end portion 21 is separated from the tin material 11, the portion of the tin material 11 melted by the end portion 21 remains on the end portion 21, and the third monitoring signal reflects whether the total amount of tin material remaining on the end portion 21 is the same as that of the end portion 21. The preset residual tin amount matches.

To sum up, the present application provides a soldering process monitoring system and method, which monitors the soldering quality through the temperature change of the end of the soldering iron during the soldering process. Therefore, when the soldering quality is not good, it can be immediately known and adjusted, which is effective. Improve the quality stability and operation efficiency of the soldering process. In addition, in this case, there is no need to use additional visual equipment for quality inspection, which can save costs.

It should be noted that the above-mentioned preferred embodiments are only proposed to illustrate the present case, and the present case is not limited to the described embodiments, and the scope of the present case is determined by the scope of the appended patent application. And this case can be modified by Shi Jiangsi, a person who is familiar with this technology, but none of them can be protected as attached to the scope of the patent application.

1: Tin feeding unit 11: Tin material 2: Soldering iron 21: End 3: Temperature sensing unit 4: Temperature controller 5: Pin 6: Solder joint 7: Processing unit (a), (b), (c), (d), (e): Action state Δt1: First time period Δt2: Second time period T1: First change amount T2: Second change amount T3: Third change amount V1: Temperature drop speed V2: Temperature recovery speed , : Mean value σ _V1 , σ _T2 , σ _V2 : Standard deviation S1, S2, S3, S4, S5, S6, S7, S8: Step

FIG. 1 is a schematic structural diagram of a soldering process monitoring system according to a preferred embodiment of the present invention.

Figure 2 is an exploded schematic diagram of the action of the soldering process.

Figure 3 is a schematic diagram of the temperature change of the tip of the soldering iron during the soldering process.

FIG. 4 is a schematic flowchart of a method for monitoring a soldering process according to a preferred embodiment of the present invention.

1: Tin delivery unit 11: Tin material 2: Soldering iron 21: End 3: Temperature sensing unit 4: Temperature controller 5: Pin 6: Solder joints 7: Processing unit

Claims (10)

A soldering process monitoring system, comprising: a tin feeding unit configured to provide a tin material; a soldering iron having one end, wherein the end is heated to melt the tin material when contacting the tin material, and the end is in contact with the tin material During a first period of time after the tin material, the temperature of the end part decreased by a first amount of change, and during the contact between the end part and the tin material, the temperature of the end part decreased by a total of a second amount variation; a temperature sensing unit configured to sense the temperature of the end of the soldering iron to obtain multiple pieces of temperature information; and a processing unit connected to the temperature sensing unit to receive the temperature information, and Calculate and obtain the first change amount and the second change amount according to the temperature information, wherein the processing unit calculates and obtains a temperature drop speed of the temperature of the end portion within the first time period, and calculates the temperature drop speed and the temperature drop speed. The second variation is compared with a first reference value and a second reference value, respectively, and a monitoring signal is output according to the comparison result, wherein the first reference value and the second reference value can pass statistical ideal soldering process The temperature drop rate, the second change amount and a temperature recovery rate in the state are obtained. The solder process monitoring system according to claim 1, wherein the monitoring signal includes a first monitoring signal, and the processing unit outputs the first monitoring signal according to a comparison result between the temperature drop rate and the first reference value, and the first monitoring signal The monitoring signal reflects whether the tip actually melts the tin material. The solder process monitoring system according to claim 1, wherein the monitoring signal includes a second monitoring signal, and the processing unit is based on the ratio of the second variation to the second reference value The second monitoring signal is output from the comparison result, and the second monitoring signal reflects whether the total amount of the tin material melted by the end portion is consistent with a preset amount of tin melting. The solder process monitoring system according to claim 1, wherein in a second time period after the end portion is separated from the tin material, the temperature of the end portion increases by a third amount of change, and the temperature sensing unit By sensing the temperature of the end to obtain a plurality of pieces of temperature information, the processing unit receives the temperature information, calculates and obtains the third variation according to the temperature information, and calculates and obtains the temperature of the end in the second For the temperature recovery speed in the time period, the processing unit compares the temperature recovery speed with a third reference value, and outputs a third monitoring signal according to the comparison result. The temperature drop speed, the second change amount and the temperature rise speed are obtained. The solder process monitoring system according to claim 4, wherein after the end portion is separated from the tin material, the portion of the tin material melted by the end portion remains on the end portion, and the third monitoring signal reflects the residual Whether the total amount of the tin material on the end is consistent with a preset residual tin amount. A soldering process monitoring method, comprising: (a) continuously sensing the temperature of an end of a soldering iron; (b) heating the end and contacting a tin material with the end, wherein the end is in contact with the tin In a first period of time after feeding, the temperature of the end is sensed to obtain a plurality of pieces of temperature information; (c) according to the temperature information, a first variation of the temperature drop in the first period of time is obtained by calculating, and calculating and obtaining the temperature drop rate within the first time period; (d) comparing the temperature drop rate with a first reference value, and outputting a first monitoring signal according to the comparison result; (e) separating the tin material from the end, wherein the temperature of the end is sensed during the process of contacting the end with the tin material, and a plurality of pieces of temperature information are obtained; and (f) according to the The temperature information calculates and obtains a second variation of the temperature drop of the end, and compares the second variation with a second reference value, and outputs a second monitoring signal according to the comparison result, wherein the first reference value and the The second reference value can be obtained by counting the temperature drop rate, the second change amount and a temperature recovery rate under an ideal solder process state. The soldering process monitoring method according to claim 6, wherein the first monitoring signal reflects whether the end portion actually melts the tin material. The solder process monitoring method according to claim 6, wherein the second monitoring signal reflects whether the total amount of the tin material melted at the end portion is consistent with a predetermined amount of tin melting. The soldering process monitoring method according to claim 6, further comprising: in a second period of time after the end portion is separated from the tin material, sensing the temperature of the end portion and obtaining a plurality of pieces of temperature information, and according to The temperature information calculates and obtains a third variation of the temperature rise of the end portion, and calculates and obtains the temperature recovery speed of the end portion within the second time period, and compares the temperature recovery speed with a third reference value, A third monitoring signal is output according to the comparison result, and the third reference value can be obtained by counting the temperature decreasing speed, the second variation and the temperature rising speed under the ideal soldering process state. The solder process monitoring method as claimed in claim 9, wherein after the end portion is separated from the tin material, the portion of the tin material melted by the end portion remains on the end portion, and the third monitoring signal reflects the residual Whether the total amount of the tin material on the end is consistent with a preset residual tin amount.

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